The shoulder is a relatively complex joint of the body, which is capable of rotation within multiple planes when the arm is displaced relative to the torso. Referring to FIG. 1, the shoulder is rotatable within three different planes of rotation, i.e., an X-Y plane containing the X and Y axes, an X-Z plane containing the X and Z axes, and a Y-Z plane containing the Y and Z axes. The Z axis has a vertical orientation aligning the Z axis in correspondence with the central longitudinal axis of a standing person. The X and Y axes both have a horizontal orientation, being perpendicular to one another and to the Z axis.
When the Z axis corresponds identically to the central longitudinal axis of a person, the X-Z plane extends longitudinally from right to left through the body of the person when standing and bisects the body into a front or anterior half Y+ and a rear or posterior half Y−, wherein the front half Y+ is forward of the X-Z plane and the rear half Y− is rearward of the X-Z plane. The Y-Z plane extends longitudinally from front to rear through the body of the person and bisects the body into a right half X− and a left half X+, wherein the right half X− is to the right side of the Y-Z plane and the left half X+ is to the left side of the Y-Z plane. The X-Z and Y-Z planes in combination divide the body into four quadrants, i.e., a right anterior quadrant X−Y+, a left anterior quadrant X+Y+, a right rear quadrant X−Y−, and a left rear quadrant X+Y−. The X-Y plane extends along a latitudinal cross-section of the body aligned in correspondence with the waistline of the body of the person, which bisects the body into an upper half Z+ and a lower half Z−, wherein the upper half Z+ is above the X-Y plane and the lower half Z− is below the X-Y plane.
Shoulder rotation is termed “external rotation” when the forearm (with the elbow flexed at about 90°) is displaced away from the anterior torso in the X-Y plane. Conversely, shoulder rotation is termed “internal rotation” when the forearm is displaced toward the anterior torso in the X-Y plane. The shoulder and associated arm are said to be at 0° external rotation (or full internal rotation) when the forearm engages or is immediately adjacent to the anterior torso. The degree of external rotation increases as the forearm swings away from the anterior torso to a maximum angle of about 180°. It is noted that the elbow and upper arm of the associated arm can remain in contact with the lateral border of the torso as the shoulder moves through external or internal rotation.
Shoulder rotation is termed “abduction” when the upper arm (independent of the condition of the elbow) is displaced away from the lateral border of the torso in the X-Z plane. Conversely, shoulder rotation is termed “abduction” when the upper arm (independent of the condition of the elbow) is displaced toward the lateral border of the torso in the X-Z plane. The shoulder and associated arm are said to be at approximately 0° abduction (or full abduction) when the elbow and upper arm engage or are immediately adjacent to the lateral border of the torso. The degree of abduction increases as the elbow and upper arm swing away from the lateral border of the torso in the X-Z plane to a maximum angle of about 135°.
Shoulder rotation is termed “flexion” when the arm (independent of the condition of the elbow) is displaced toward the anterior torso in the Y-Z plane. Conversely, shoulder rotation is termed “extension” when the arm is displaced away from the anterior torso in the Y-Z plane. The shoulder and associated arm are said to be at approximately 0° extension (or full flexion) when the elbow and upper arm engage or are immediately adjacent to the lateral border of the torso, i.e., when the upper arm is hanging at the side and lies in the X-Z plane. The degree of extension increases as the upper arm swings away from the anterior torso in the Y-Z plane to a maximum angle of about 180°.
Although the rotational capabilities of the shoulder recited above advantageously enhance the function of the joint, the same expansive rotational capabilities also complicate treatment of the shoulder following injury or surgery. Treatment frequently requires determining a desired optimal healing position of the shoulder and associated arm, placement of the shoulder and associated arm in the desired healing position, and immobilization of the shoulder and arm in the desired healing position. Such a recuperative treatment is particularly applicable to soft tissue injuries involving damage to one or more connective shoulder ligaments and furthermore is oftentimes the treatment of choice following any number of surgical procedures, including surgery for recurrent posterior subluxation, rotator cuff surgery, humeral head or shaft fracture correction, and the like. Healing occurs inter alia through diminution of inflammation and/or regeneration of muscle tissues, which is promoted by removing stress from the injured or surgically corrected joint.
Support devices, such as orthopedic braces, rigid casts, slings and the like, are commonly employed to perform the above-recited placement and immobilization function with varying degrees of success. For example, rigid casts, which are typically molded plaster or resin, have traditionally been used as joint immobilizers. The rigid cast may be replaced from time to time as swelling is reduced. However, the disadvantages of rigid casts are well known. Rigid casts are heavy and uncomfortable to wear and are relatively laborious and complex to apply. Rigid casts may also unduly limit the mobility of the patient and cause joint stiffening and muscle atrophy. In addition, wound and skin treatments and bathing must usually be postponed until the rigid cast is removed.
Support devices using synthetic thermoformable materials are lighter and stronger than rigid casts. However, such devices are significantly more complex and costly. The basic stock materials for constructing the devices are relatively expensive and construction of the devices requires molding all of the constituent parts piece by piece from the stock materials while very hot. The resulting constituent parts are then subsequently joined piece by piece again using heat. Adjusting the fit of the device requires cutting off excess material once the device is in place which can produce sharp edges. In addition, such devices, like rigid casts, can only be used once.
Support devices using metal components are likewise costly and are also relatively heavy. In addition the metal components must be made to order and are typically assembled in an articulated configuration necessitating many fasteners, such as screws, nuts, and bolts, which require significant adjustment.
The present invention recognizes a need for a shoulder orthosis, which is simple, light-weight, and relatively inexpensive, yet highly stable for desired post-surgical or post-injury management of the shoulder. Accordingly, it is an object of the present invention to provide an orthosis for an arm and shoulder which effectively immobilizes the arm and shoulder while accurately positioning the shoulder joint to promote healing and curtail pain. More particularly, it is an object of the present invention to provide an orthosis for an arm and shoulder which restrains the arm, elbow joint and shoulder joint in a more stable position than prior art orthoses. It is another object of the present invention to provide an orthosis for an arm and shoulder which will fit the great majority of patients with a single size and which is adaptable for either the left or the right side of the patient. It is another object of the present invention to provide an orthosis for an arm and shoulder which is light-weight and is easily fitted to the patient. These objects and others are accomplished in accordance with the invention described hereafter.